Knowledge Bank

It is well known that the near ultraviolet absorption spectrum (3000-4000 \AA) consists of two band systems, $a\sim 3A2-X\sim 1A1$ and $A\sim 1A2-X\sim 1A1$. Detailed analyses exist for a large number of the bands of the latter $system1$ but rotational analyses have previously been carried out for only the $000$ and $402(0+and 1+)$ bands of the triplet-singlet $system.2,3$ In the present work, we have completed the rotational analyses of five new bands, viz., $201$, $201402$, $201404$, $404$ and a band in Fermi resonance with $201404$. Some Coriolis perturbations have also been found. The analyses of these bands will be discussed and the rotational and vibrational constants will he given. Further high resolution studies are being carried out on magnetically sensitive lines in the region 3000-3500 \AA , as an aid in identifying triplet-singlet perturbations.